[iOS] Fix Incognito Search action

The action was wrongly created, leading to opening the search in
non-incognito.

Fixed: 1402647
Change-Id: I275f8ddcfb01e9d2da95aa12a0bac79d8df25b88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4120256
Commit-Queue: Ewann Pellé <ewannpv@chromium.org>
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Ewann Pellé <ewannpv@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1085949}

Author: Gauthier Ambard

ios/chrome/browser/ui/menu/browser_action_factory.mm

@@ -304,7 +304,7 @@ - (UIAction*)actionToStartNewIncognitoSearch {
                        type:MenuActionType::StartNewIcognitoSearch
                       block:^{
                         OpenNewTabCommand* command =
-                            [OpenNewTabCommand commandWithIncognito:NO];
+                            [OpenNewTabCommand commandWithIncognito:YES];
                         command.shouldFocusOmnibox = YES;
                         [handler openURLInNewTab:command];
                       }];